b) The .gfs2_admin directory exposes the internal files that GFS uses
to store various bits of file system related information. This means
that we've been able to remove virtually all the ioctl() calls from
GFS2. There is one ioctl() call left which relates to
getting/setting GFS2 specific flags on files. The various GFS2 tools
will be updated in due course to use this new interface.
Without even looking at the code a strong NACK here. This is polluting
the namespace which is not acceptable. Please implement a second
filesystem type gfsmeta to do this kind of admin work. Search for ext2meta
which did something similar. Or use a completely different approach,
I'd need to look at the actual functionality provided to give a better
advice, but currently I'm lacking the time for that.